JP2010166640A - Overhead transmission line and construction method at periphery of steel tower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an overhead transmission line superior in construction property, security and workability and to provide a construction method at periphery of a steel tower. <P>SOLUTION: In the overhead transmission line, steel tower side end parts of overhead transmission lines 31, which are arranged across the steel tower, are supported by the steel tower through insulators 30. The transmission line is provided with the established insulators 30, a supporting unit 50 coupling a part detached from the steel tower, i.e., the overhead transmission line 31, supporting the overhead transmission line 31 on a side detached from the steel tower from the part in a stretched state and having a temporary insulator 9, fixing members 18 and 23 which are removed from the established insulators 30 and fix a part of the overhead transmission line 31 comprising the steel tower side end part pulled back to an overhead transmission line 31 side in the stretched state by the supporting unit 50 to the overhead transmission lines 31 in the stretched state, and a jumper unit 60 which is disposed across the steel tower 50, electrically connects the overhead transmission lines 31 supported in the stretched states by the supporting unit 50 and has a cable with metal cover 26. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an overhead power transmission line and a construction method around a steel tower, and in particular, an overhead power transmission line that can secure an electrically safe area around the steel tower prior to the work around the steel tower, and a work around the steel tower using the overhead power transmission line. Regarding the method.

  In recent years, because of the aging of overhead transmission lines and the close proximity of transmission lines and ground structures due to the expansion of urbanization, so-called ground clearance shortages, repair work of overhead transmission lines (reconstruction and remodeling of towers, Electric wire replacement, steel tower maintenance painting work, armrest remodeling and replacement, etc.) are increasing. Conventionally, when performing these repair work, in order to secure a work safety space and shorten the power outage period, the overhead power transmission line has been temporarily moved to a temporary iron pole, a temporary iron tower, a temporary arm metal, etc. Temporary work to separate the transmission line is underway. However, this temporary work has a problem that it takes a lot of cost and time to construct and remove the temporary towers and to negotiate the land. Furthermore, in urban areas, there is no space for constructing temporary towers, etc., and there are places where temporary work and thus repair work is difficult to implement.

  Therefore, the present applicant uses a metal shielded cable (moving cable) having an air termination part as a jumper wire of the overhead power transmission line, and sufficiently connects the connection part between the metal shielded cable and the overhead power transmission line from the tower. A temporary construction method has been devised and put into practical use that can secure a work safety space in the vicinity of the steel tower without using a temporary steel tower, a temporary iron pillar, and a temporary arm metal by separating them (see, for example, Patent Document 1).

In this temporary construction method, as shown in FIG. 6, the transmission line 100 in the vicinity of the tower 110 is jumpered by a metal shielded cable 113 with insulation coating, so that work such as rebuilding the tower can be performed safely even in an energized state. It is possible to construct. 6 (a) is a schematic plan view, and FIG. 6 (b) is a perspective view (in FIG. 6 (b), one power transmission line is shown by a solid line, and the other power transmission line is a transmission line. Only the electric wire 100 is indicated by a chain line.)
That is, in this temporary construction method, the insulator device 112 at the end of the steel tower is separated from the steel tower 110 by about 10 m to 15 m by the support wire 111 such as a steel stranded wire connected to the arm metal 115 of the steel tower 110, and the steel tower 110. By connecting the electrical connection between the power transmission lines 100 with the metal shielded cable 113 covered with insulation, the vicinity of the steel tower 110 is made non-voltage. The cable heads 114 provided at both ends of the metal shielded cable 113 are suspended from the lever device 112 at the end of the power transmission line 110, and the metal shielded cable 113 is suspended from the support line 111 by a hanger. Thus, a work safety space can be secured in the vicinity of the steel tower 110 even in the energized state, and work such as steel tower rebuilding can be performed.

JP 2000-270454 A

However, according to the temporary construction method in Patent Document 1, when both ends of the metal shielded cable 113 suspended from the support line 111 are fixed to the existing power transmission line, about 10 to 15 m from the steel tower respectively. The electric wire 110 was cut and removed even when functioning normally.
When the construction work is completed, it is necessary to attach a new power transmission line (cable) corresponding to the cut distance again, and the cost for attaching the new power transmission line to the construction cost is excessive. In addition, on construction, it will be work over the overhead line away from the tower,
Careful attention is required in terms of workability, safety, and workability.
In addition, the nature of construction, such as when working at a short distance from the tower support position, such as maintenance painting work on steel towers, painting of insulator brackets, replacement of insulators, modification or replacement of arm brackets (arms), etc. Depending on the content, it may not be necessary to secure a no-voltage region of about 10 m to 15 m from both sides of the steel tower until the existing transmission line that functions normally is cut.

  An object of the present invention is to provide an overhead power transmission line that is low in cost and excellent in workability, safety, and workability without cutting an existing overhead power transmission line, and a construction method around a steel tower using the overhead power transmission line. It is to provide.

  In order to solve the above problems, the present invention is configured as follows.

  According to a first aspect of the present invention, the tower-side end portion of the overhead power transmission line arranged across the steel tower is in an overhead power transmission line supported by the steel tower via an insulator, and the existing insulator and A support unit having a temporary insulator that connects between the overhead power transmission line at a part away from the steel tower and supports the overhead power transmission line on the side away from the steel tower from the part in a tightly connected state; and A portion of the overhead power transmission line including the tower side end portion removed from the insulator and pulled back to the overhead power transmission line side in a tight line state by the support unit is connected to the overhead power transmission line in a tight line state. A fixing member for fixing, and a jumper unit having a cable with metal shielding, which is disposed between the steel towers and electrically connects between the overhead power transmission lines supported in a tight state by the support unit. Is Is an overhead power transmission line you are.

  According to a second aspect of the present invention, in the overhead power transmission line according to the first aspect, terminal connection portions provided at both ends of the metal shielded cable, and the overhead power transmission line in a tight state by the support unit, Between are overhead transmission lines that are electrically connected by jumper wires.

  According to a third aspect of the present invention, the tower-side end of the overhead power transmission line arranged across the steel tower is an overhead power transmission line supported by the steel tower via an insulator, and the existing insulator and A support unit having a temporary insulator that connects between the overhead power transmission line at a part away from the steel tower and supports the overhead power transmission line on the side away from the steel tower from the part in a tightly connected state; and the steel tower And a jumper unit having a metal shielded cable for electrically connecting the overhead power transmission lines supported in a tightly connected state by the support unit. The tower side end of the overhead power transmission line is an overhead power transmission line that is electrically connected to the metal shielded cable of the jumper unit.

  According to a fourth aspect of the present invention, in the overhead power transmission line according to the third aspect, the tower side end of the overhead power transmission line removed from the existing insulator and both ends of the metal shielded cable are provided. The terminator connection portion is an aerial transmission line connected by a connection terminal.

  According to a fifth aspect of the present invention, in the overhead power transmission line according to the third or fourth aspect, a ground line electrically connected to the metal shielding layer of the metal shielded cable extends along the metal shielded cable. It is an aerial transmission line that is wired and grounded to the steel tower.

  According to a sixth aspect of the present invention, in the overhead power transmission line according to the second, fourth, or fifth aspect, the terminal connection portion is suspended from the temporary insulator of the support unit via a support member. It is a transmission line.

According to a seventh aspect of the present invention, there is provided a construction method for a periphery of a steel tower including an overhead power transmission line that is supported by the steel tower via an insulator on each side of the power transmission tower arranged between the steel towers. And connecting between the existing insulator and the overhead power transmission line in a part away from the steel tower using a support unit having a temporary insulator, and connecting the overhead power transmission line on the side away from the steel tower from the part. A step of supporting in a tightly connected state, and removing the tower side end of the overhead power transmission line from the existing insulator, and the removed overhead side of the tower is in a tightly connected state by the support unit The portion of the overhead power transmission line including the tower side end pulled back is fixed to the overhead power transmission line in a tight line state by a fixing member, and is disposed across the tower. Depending on the support unit A step of electrically connecting between the overhead power transmission lines supported in a line state using a jumper unit having a metal shielded cable, and after these steps, construction around the tower is performed. This is the construction method around the steel tower.

  According to an eighth aspect of the present invention, there is provided a construction method for a periphery of a steel tower including an overhead power transmission line that is supported by the steel tower via an insulator on each side of the power transmission tower arranged between the steel towers. And connecting between the existing insulator and the overhead power transmission line in a part away from the steel tower using a support unit having a temporary insulator, and connecting the overhead power transmission line on the side away from the steel tower from the part. A step of supporting in a tight line state, and passing through the tower in order to electrically connect the overhead power transmission lines arranged between the towers and supported in the tight line state by the support unit. A step of installing a jumper unit having a cable with metal shielding to be wired, and removing the tower side end of the overhead power transmission line from the existing insulator, and removing the removed tower side end from the metal shielding cable Both ends of And a step of electrically connecting the terminal connecting portion provided, after these steps, a construction method of tower around which is characterized in that the construction around the tower.

  According to a ninth aspect of the present invention, in the construction method around the steel tower according to the seventh or eighth aspect, in the connecting step, the grounding wire electrically connected to the metal shielding layer of the metal shielded cable, It is a construction method around a steel tower including a step of wiring along a metal shielded cable and grounding to the steel tower.

  According to the present invention, it is possible to easily secure an electrically safe area around a steel tower without cutting an existing overhead power transmission line, and it is excellent in workability, safety and workability, and can be quickly restored. The construction method around the transmission line and the tower can be realized.

It is a figure which shows an example of the state of the overhead power transmission line around a steel tower before the construction around a steel tower (existing state). The state of the overhead power transmission line in the first embodiment after construction (temporary construction) to secure an electrically safe work area around the steel tower before construction around the tower (main work) is shown. FIG. In 1st Embodiment, it is a figure which shows the PG clamp used for the connection of a jumper wire and an overhead power transmission line. The state of the overhead power transmission line in the second embodiment after construction (temporary construction) for securing an electrically safe work area around the tower before construction (main construction) around the tower is shown. FIG. In 2nd Embodiment, it is a perspective view for demonstrating the connection of a cable head end part and a compression type clamp using a special connection terminal. FIG. 6 (a) is a schematic plan view showing a conventional temporary construction method for securing an electrically safe work area around the steel tower before construction around the tower (main work). 6 (b) is a perspective view.

  Hereinafter, an embodiment of a construction method around an overhead power transmission line and a steel tower according to the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram illustrating an example of an overhead power transmission line around a steel tower in a state (existing state) before construction around the steel tower.
As shown in FIG. 1, the compression-type retention clamp 19 at the tower-side end of the overhead power transmission line 31 arranged across the tower 90 is connected to the armature of the tower 90 via the insulator-linking device (insulator) 30. Arms 91 are supported respectively. A jumper wire 33 is connected between the jumper terminals 19a, 19a of the compression type retaining clamps 19, 19 on both sides of the steel tower 90.

Fig. 2 shows the construction around the tower, ie maintenance painting of the tower, painting of the lion metal fittings, replacement of the insulator, remodeling and replacement of the armor, and other works such as rebuilding and remodeling of the tower and replacement of the transmission line It is a figure which shows the state of an aerial transmission line after performing construction (temporary construction) for securing an electrically safe work area around a steel tower prior to performing (main construction).
In FIG. 2, only the overhead power transmission line on one side of the tower (not shown in FIG. 2) is illustrated, but as shown in FIG. 1, symmetrically with respect to the center line of the tower 90 on both sides of the tower 90. An overhead power transmission line is arranged. In FIG. 2, the insulator series device 30 is an existing insulator series device 30 connected to the arm 91 of the steel tower 90 before construction around the steel tower shown in FIG. 1, and the overhead power transmission line 31 is also shown in FIG. 1. This is an overhead power transmission line 31.

Between the existing insulator-linking device 30 and the overhead power transmission line 31 at a site away from the steel tower (attachment site of the wedge-shaped retention clamp 21), these are connected to the overhead power transmission cable 31 on the side farther from the steel tower than the above site. A support unit (first unit) 50 having a long insulator 9 as a temporary insulator is provided. In addition, the shape of the long trunk insulator 9 is not limited to that shown in FIG. 1 or FIG. 4, and the same shape as the existing insulator 30 can be used.
The portion of the overhead power transmission line 31 on the pylon side from the portion including the compression type retaining clamp 19 removed from the existing insulator linkage device 30 is pulled back by the support unit 50 to the overhead power transmission line 31 side which is in a tightly connected state. These are fixed to the overhead power transmission line 31 in a tight-wire state by the fixing metal fitting 18 and the aluminum binding wire 23 as a fixing member.
In addition, a CJ-CV cable (cross-linked polyethylene insulation) as a metal shielded cable that is disposed between steel towers and is electrically connected between the overhead power transmission lines 31 and 31 supported in a tightly connected state by the support unit 50. A jumper unit (second unit) 60 having a vinyl sheath cable 26 is provided.

The support unit 50 has a long insulator 9 at the center, the ground wire tension clamp 1 connected to the end of the existing insulator linkage device 30 on the steel tower side, and the overhead wire on the power transmission line side away from the steel tower. A wedge-shaped retention clamp 21 attached to the power transmission line 31 is provided.
An arc horn 8 for preventing damage to the long trunk insulator 9 due to lightning strikes is provided at the end of the long trunk insulator 9 on the steel tower. The arc horn 8 includes a horn mounting bracket 7, parallel clevis 6, triangular link 5. The compression clamp 3 is provided via the parallel clevis 4. Between the compression clamp 3 and the ground wire tension clamp 1, a galvanized steel strand 2 is bridged as a ground wire, and the galvanized steel strand 2 further passes through the ground wire tension clamp 1. It is installed on a steel tower.
For example, an arc horn 10 is provided at the end of the long trunk insulator 9 on the power transmission line side away from the steel tower. The arc horn 10 has a special single link 11, a parallel clevis 12, a parallel clevis link 13, and a single link. 14, a wedge-shaped retention clamp 21 is provided via an appropriate wire bracket series such as the Y-shaped bracket 15 and the single link 16.

The overhead power transmission line 31 that has passed through the wedge-shaped retention clamp 21 and is already installed closer to the steel tower than the wedge-shaped retention clamp 21 is pulled back to the overhead power transmission line 31 side that is in a tight connection state by the support unit 50, and The compression type retaining clamp 19 fixed to the overhead power transmission line 31 in the tight line state and the tower side end of the overhead power transmission line 31 is fixed to the overhead power transmission line 31 in the tight line state by the aluminum bind wire 23. ing. Here, the tight line state means a state in which it is in tension with an appropriate tension that contributes to power transmission through the transmission line.

  The jumper unit 60 includes a CJ-CV cable 26 having a metal shielding layer (not shown), a cable head 25 as a terminal connection provided at both ends of the CJ-CV cable 26, and a power transmission line side of the cable head 25. A jumper wire 22 is provided for connecting the end and the overhead power transmission line 31 in a tight-wired state.

The CJ-CV cable 26 is, for example, a central conductor (flexible stranded conductor (outer diameter 26.0 mm)
And an insulator covering the periphery of the central conductor (consisting of an inner semiconductive layer and an outer semiconductive layer, and having a thickness of 13.
0mm) and a braided structure shielding layer covering the periphery of the insulator (an annealed copper wire braided sheath (thickness: 4.0 mm))
) And a cable (total cable outer diameter 66 mm) in which a pressing tape is wound around the outer periphery of the braided structure shielding layer. In addition, this cable structure is only an example, and the thickness and the outer diameter are appropriately changed according to the use environment.

The end of the jumper line 22 on the power transmission line side is electrically connected to the overhead power transmission line 31 by the PG clamp 20.
The PG clamp 20 has a structure as shown in FIG. 3, for example. In other words, two clamp members 20a and 20a made of metal are provided, and two semicircular cross-section grooves are formed in parallel on the press-contacting surfaces of the clamp members 20a and 20a, respectively. When the pressure contact surfaces of the members 20a and 20a are overlapped, as shown in FIG. 3, two circular electric wire insertion ports 20c and 20c are formed vertically. An overhead power transmission line 31 is inserted into the upper insertion port 20c, and a jumper wire 22 is inserted into the lower insertion port 20c. By tightening the three bolts 20b provided at the upper, middle and lower portions of the clamp member 20a, The overhead power transmission line 31 and the jumper line 22 are connected and fixed.
The jumper wire 22 is not particularly limited, and may be a bare wire, an insulation-coated wire, or a cable with a shielding layer. For the overhead power transmission line 31, an aluminum wire, a steel core aluminum stranded wire, or the like is used.

The cable head 25 is suspended below the long insulator 9 of the support unit 50 substantially in parallel with the long insulator 9 by a turnbuckle 17 as a support member and the cable head fixing bracket 24.
As the cable head 25, a 77 kV air porcelain insulator cable head (for example, a weight of about 200 kg) used in general power equipment, a 77 kV moving mold cable head that is light and easy to handle, or the like is used.

  An end portion of the ground wire 27 electrically connected to a metal shielding layer (not shown) of the CJ-CV cable 26 is connected to the galvanized steel stranded wire 2 by a bolt connector 28. The galvanized steel stranded wire 2 is fixed to the ground wire tension clamp 1 on the way and is grounded to a steel tower.

Next, an operation (temporary work) for forming the overhead power transmission line shown in FIG. 2 will be described.
Before this temporary construction work (existing state), as shown in FIG. 1, the compression type retaining clamp 19 at the tower side end of the overhead power transmission line 31 is attached to the insulator linkage device 30 and attached to the arm 91 of the tower 90. A jumper wire 33 is connected between the compression type retaining clamps 19 and 19 on both sides of the steel tower 90.

  For example, the temporary work is performed in the following procedure.

(I) The support unit 50 is attached to the existing overhead power transmission line 31 and the existing overhead power transmission line 31 is removed from the existing insulator linkage device 30.
Specifically, the ground wire tension clamp 1 is attached to the existing insulator linkage device 30, and the wedge-type retention clamp 21 is attached to the existing overhead power transmission line 31. At this time, the overhead power transmission line 31 is drawn to the tower side, and the wedge-shaped position is set so that the existing overhead power transmission line 31 is longer than the entire length of the support unit 50 with reference to the existing insulator linkage device 30. A tension clamp 21 is attached. Thereby, the overhead power transmission line 31 on the side farther from the steel tower than the wedge-shaped retention clamp 21 is supported in a tightly connected state by the support unit 50. Moreover, the steel strand 2 is connected to a steel tower.
The compression-type retention clamp 19 attached to the existing overhead power transmission line 31 is removed from the existing insulator linkage device 30. At this time, the overhead transmission line 31 on the side farther from the steel tower than the wedge-type retention clamp 21 is supported by the support unit 50 in a tightly connected state, and the wedge is removed from the compression-type retention clamp 19 attached to the end of the insulator linkage device 30. Since the overhead power transmission line 31 up to the mold retaining clamp 21 is in a loose state, the compression type retaining clamp 19 can be easily detached from the lever linkage device 30.

(Ii) The jumper unit 60 is attached to the support unit 50.
The cable head 25 is suspended from both ends of the long trunk insulator 9 of the support unit 50 using the cable head fixing bracket 24 and the turnbuckle 17. With this structure, since the CJ-CV cable 26 is short, no support wire is particularly provided and a hanger is not required separately. Since the length of the turnbuckle 17 is adjustable, the vertical position of the cable head 25 terminal portion relative to the long insulator 9 can be adjusted. In addition, the ground wire 27 electrically connected to the metal shielding layer of the CJ-CV cable 26 is connected to the steel stranded wire 2 of the support unit 50 by the bolt connector 28.

(Iii) The jumper unit 60 is connected to the existing overhead power transmission line 31.
Specifically, one end of the jumper wire 22 is attached to an existing overhead power transmission line 31 in a tight-wired state using the PG clamp 20 (the same applies to the opposite side not shown). As a result, the overhead power transmission lines 31 on both sides of the steel tower are electrically connected by the jumper unit 60. Thereafter, the existing jumper wire 33 attached across the steel tower 90 shown in FIG. 1 is removed.

(Iv) The removed overhead power transmission line 31 from the compression-type tension clamp 19 to the wedge-type tension clamp 21 is moved to the overhead power transmission line 31 side supported by the support unit 50 in a tightly connected state without being cut or discarded. It bends around and turns around, and is fixed to the overhead power transmission line 31 in a tight connection state using a plurality of fixing fittings 18 such as a PG clamp.
The minimum bending radius (allowable bending radius) of the overhead power transmission line 31 removed from the steel tower, which is bent so as to be folded back to the side of the overhead power transmission line 31 supported in a tight-wire state, is at least eight times the outer diameter of the electric wire. Good. This is to prevent bending, bending, and laughing (a twist in the wire element is returned and a gap is generated in the twist) or the like when the overhead power line 31 is bent. Thus, the existing overhead power transmission line 31 can be used in the same manner as before the construction without being damaged. The interval between the fixed portions of the overhead power transmission lines 31 by the plurality of fixing brackets 18 is preferably 2 m or less. This is because the separation from other overhead power transmission lines 31 and the like can be ensured even when the fixation at one place is removed.
Further, the compression type retaining clamp 19 at the end of the removed overhead power transmission line 31 is fixed to the overhead power transmission line 31 in the tightly connected state by using the aluminum bind wire 23.

  When this work (temporary work) is completed, an electrically safe work area is secured around the tower, so maintenance painting work for the tower 90, painting of the insulator linkage device 30, replacement of the insulator, and modification of the arm metal 91・ Start substantive work (main work) such as replacement.

  When the main construction work is completed, the work is returned to the original state by working backward the procedure of the temporary work. For example, it is as follows.

(I) The fixing bracket 18 and the aluminum binding wire 23 are removed, and the overhead power transmission line 31 that is folded and fixed is removed from the overhead power transmission wire 31 in the tightly connected state.
(Ii) The existing jumper wire 33 is attached between the compression type retaining clamps 19, 19 across the steel tower 90.
(Iii) The jumper wire 22 of the jumper unit 60 is removed from the overhead power transmission line 31 in the tight line state.
(Iv) The jumper unit 60 is removed from the support unit 50.
(V) While removing the support unit 50 from the existing insulator linkage device 30 and the overhead power transmission line 31, the removed existing compression retention clamp 19 is attached to the end of the existing insulator linkage device 30.

  Thus, temporary work can be performed without cutting the overhead power transmission line 31, so that the original existing state can be restored at a low cost and in a short time. Accordingly, the overhead power transmission line can be immediately restored even in an emergency, and a quick response is possible.

(Second Embodiment)
FIG. 4 is a diagram showing the state of the overhead power transmission line in the second embodiment after temporary work for securing an electrically safe work area around the steel tower is performed before the main work around the steel tower. is there. The state (existing state) before the main construction around the steel tower is the same as that in FIG. 1 in the first embodiment.

The overhead power transmission line of the second embodiment shown in FIG. 4 is different from the overhead power transmission line of the first embodiment shown in FIG.
That is, the overhead power transmission line 31 from the wedge-shaped retention clamp 21 removed from the steel tower to the existing compression-type retention clamp 32 is fixed to the overhead power transmission line 31 side supported by the support unit (first unit) 70 in a tightly connected state. Without connecting to the end of the cable head 25 of the jumper unit (second unit) 80, without using the ground wire 27, and with the shielding layer of the cable with metal shielding (CJ-CV cable) 26 A shield layer conductor ground (grounding conductor) 34 to be electrically connected is provided, and the grounding conductor 34 is grounded to a steel tower.

Also in the second embodiment, the support unit 70 connects between the existing insulator-linking device 30 and the overhead power transmission line 31 at a site away from the steel tower (attachment site of the wedge-shaped retention clamp 21). The overhead power transmission line 31 on the side farther from the steel tower is supported in a tightly connected state.
For example, the support unit 70 includes a long trunk insulator 9, arc horns 8 and 10 disposed on both sides of the long trunk insulator 9, a horn mounting bracket 7 provided on the arc horn 8 on the steel tower side, and a transmission line side. The arc horn 10 is connected to a special one-piece link 11, a parallel clevis 12, a parallel clevis link 13, a one-piece link 14, a Y-shaped fitting 15, and an appropriate overhead wire fitting series such as a one-piece link 16. And a wedge-shaped retaining clamp 21 provided.
The horn mounting bracket 7 is attached to the existing insulator linkage device 30, and the wedge-type retention clamp 21 is fixed to the existing overhead power transmission line 31.

The jumper unit 80 is arranged across a steel tower, and is a metal shielded cable (CJ-CV cable) 26 that electrically connects between the overhead power transmission lines 31 and 31 supported in a tight line state by the support unit 70. Terminal connection portions (cable heads) 25 provided at both ends of the CJ-CV cable 26, connection terminals (special connection terminals) 40 provided at the transmission line side end portions of the cable head 25, and the cable head 25. And a shield layer conductor ground (grounding conductor) 34 that is electrically connected to the shield layer of the CJ-CV cable 26 at the terminal connection portion between the CJ-CV cable 26 and wired along the CJ-CV cable 26. I have.
An existing compression-type retention clamp 32 serving as a steel tower side end of the overhead power transmission line 31 and a power transmission line side end of the cable head 25 are connected by a special connection terminal 40. The grounding conductor 34 is grounded to the steel tower.

In FIG. 5, the perspective view for demonstrating the connection of the cable head 25, the special connection terminal 40, and the compression type | mold retention clamp 32 is shown. One end portion 40 b of the special connection terminal 40 is connected to the terminal 25 a on the power transmission line side of the cable head 25, and the other end portion 40 a of the special connection terminal 40 is connected to the existing compression type tension clamp 32.
One end portion 40b of the special connection terminal 40 on the cable head 25 side has a rectangular flat plate shape, and for example, screw holes are formed at four points. The terminal 25a of the cable head 25 is also a rectangular flat plate and has screw holes formed at four points. The one end 40b of the special connection terminal 40 and the terminal 25a of the cable head 25 are overlapped and fixed by screwing.
The existing compression type clamp 32 is made of aluminum and has a through hole. An overhead power transmission line 31 is inserted from one end side of the through hole, and a tapered terminal 32a made of steel is inserted from the other end side of the through hole. A flange 32b is formed on the distal end side of the compression type clamping clamp 32, and two screw holes are formed in the flange 32b. Further, the other end portion 40a of the special connection terminal 40 on the side of the compression type tension clamp 32 is a U-shaped terminal having a screw hole formed at two points. The compression-type retention clamp 32 and the special connection terminal are fixed by inserting the flange 32b of the compression-type retention clamp 32 into the U-shaped other end portion 40a of the special connection terminal 40 and screwing it. Here, since the flange 32b substantially orthogonal to the main body portion of the compression type retaining clamp 32 is attached to the other end portion 40a of the special connection terminal 40, the overhead power transmission line 31 is bent and deviated.

  The jumper unit 80 is suspended from the support unit 70 by fixing the turnbuckle 17 and the cable head fixing bracket 24 to both ends of the cable head 25 and attaching them to both ends of the long trunk insulator 9 of the support unit 70.

  With the structure of the overhead power transmission line shown in FIG. 4, the fixing bracket 18 for folding the existing power transmission line 31 in the first embodiment and fixing it to the existing power transmission line 31 in a tightly connected state, an aluminum bind line 23 is unnecessary, and the tower side end of the existing overhead power transmission line 31 is directly connected to the cable head 25, so that the jumper wire 22 and the PG clamp 20 are unnecessary, and further, the ground wire 27, galvanized steel Since the stranded wire and the ground wire tension clamp 12 are not required, the number of components can be reduced. Further, as in the first embodiment, the existing overhead power transmission line 31 is not cut, and it is not necessary to bend and route the existing overhead power transmission line 31, so there is an advantage that a non-voltage region can be realized in a compact manner. . Further, it is possible to realize construction (construction) at a short distance from the steel tower support position as compared with the first embodiment.

  In the second embodiment, the temporary work is performed in the following procedure, for example. The existing state before construction work is the same as FIG.

(I) While attaching the support unit 70 to the existing overhead power transmission line 31, the existing overhead power transmission line 3
1 is removed from the existing insulator linkage device 30.
The horn mounting bracket 7 is attached to the existing insulator linkage device 30 and the wedge-type retention clamp 21 is fixed to the existing overhead power transmission line 31, as in the first embodiment. The overhead power transmission line 31 on the far side is supported by the support unit 50 in a tight line state.
(Ii) The jumper unit 80 is attached to the support unit 70.
The cable head 25 is suspended from both ends of the long insulator 9 of the support unit 70 using the cable head fixing bracket 24 and the turnbuckle 17. Also, the grounding conductor 34 is connected to the CJ-CV.
Wire along the cable 26 and connect to the tower.
(Iii) Connect the removed existing overhead power transmission line 31 to the jumper unit 80. Specifically, the flange 32 b of the existing compression type retaining clamp 32 of the overhead power transmission line 31 and the terminal 25 a on the power transmission line side of the cable head 25 are connected using the special connection terminal 40. As a result, the overhead power transmission lines 31 on both sides of the steel tower are electrically connected by the jumper unit 80. Thereafter, as shown in FIG. 1, the existing jumper wire 33 attached across the steel tower 90 is removed.

  When the above temporary work is completed, an electrically safe work area is secured around the tower, so the maintenance painting work for the tower 90, the painting of the insulator linkage device 30, the replacement of the insulator, the modification and replacement of the arm metal 91, etc. Start substantive main construction work. Further, after the completion of the main construction work, it is possible to return to the original state by working backward the procedure of the temporary construction as in the first embodiment.

  As described above, since the work of bending the existing overhead power transmission line 31 and attaching it to the overhead power transmission line 31 in the tight connection state is not required as in the first embodiment, workability is improved. Further, since the grounding of the cable with the shielding layer (CJ-CV cable) 26 is routed from the jumper unit, not the support unit, to the steel tower, it is not necessary to provide a grounding space on the support unit side as in the first embodiment. In the second embodiment, it is possible to perform an operation suitable for non-voltage at a location closer to the steel tower.

  In addition, the overhead power transmission line of the above embodiment and the construction method around the steel tower using this are the construction work such as the maintenance painting work of the steel tower, the painting of the insulator unit, the replacement of the insulator, the modification and the replacement of the armrest, etc. In addition, it can be applied to work with single line charging and safety measures when the lower line is live.

1 Tensile clamp for ground wire 2 Zinc-plated steel stranded wire 8, 10 Arc horn 9 Long trunk insulator (temporary insulator)
17 Turnbuckle 18 Fixing bracket 19 Compression type clamping clamp 20 PG clamp 21 Wedge type clamping clamp 22 Jumper wire 23 Aluminum binding wire 24 Cable head fixing bracket 25 Cable head 26 CJ-CV cable (cable with metal shield)
30 Isogo device (existing insulator)
31 Overhead Transmission Line 32 Compression Type Retention Clamp 34 Grounding Conductor 40 Connection Terminals 50, 70 Support Units 60, 80 Jumper Unit 90 Steel Tower 91 Arm (arm)

Claims (9)

The tower side end of the overhead power transmission line arranged across the steel tower is in the overhead power transmission line supported by the steel tower via the insulator,
A support having a temporary insulator that connects between the existing insulator and the overhead power transmission line at a part away from the tower, and supports the overhead power transmission line on the side farther from the tower than the part in a tightly connected state. Unit,
A part of the overhead power transmission line including the tower side end portion removed from the existing insulator and pulled back to the overhead power transmission line side in a tight line state by the support unit is connected to the overhead transmission in the tight line state. A fixing member for fixing to the electric wire;
A jumper unit having a metal shielded cable, which is disposed between the towers and electrically connects between the overhead power transmission lines supported in a tight state by the support unit. An overhead power transmission line.   A terminal connection portion provided at both ends of the metal shielded cable and the overhead power transmission line in a tight line state by the support unit are electrically connected by a jumper wire. The overhead power transmission line according to claim 1. The tower side end of the overhead power transmission line arranged across the steel tower is in the overhead power transmission line supported by the steel tower via the insulator,
A support having a temporary insulator that connects between the existing insulator and the overhead power transmission line at a part away from the tower, and supports the overhead power transmission line on the side farther from the tower than the part in a tightly connected state. Unit,
A jumper unit having a metal shielded cable, which is disposed between the towers and electrically connects between the overhead power transmission lines supported in a tight line state by the support unit, is provided,
The overhead power transmission line, wherein the tower side end portion of the overhead power transmission line removed from the existing insulator is electrically connected to the metal shielded cable of the jumper unit.   The tower side end of the overhead power transmission line removed from the existing insulator and the terminal connection provided at both ends of the metal shielded cable are connected by a connection terminal. The overhead power transmission line according to claim 3.   5. The grounding wire electrically connected to the metal shielding layer of the metal shielded cable is wired along the metal shielded cable and grounded to the steel tower. 6. Overhead power transmission line.   The overhead power transmission line according to claim 2, 4 or 5, wherein the terminal connection portion is suspended from the temporary insulator of the support unit via a support member. A steel tower side end of an overhead power transmission line arranged across a steel tower is a construction method around a steel tower provided with an overhead power transmission line supported by the steel tower via insulators,
A connection unit between the existing insulator and the overhead power transmission line at a site away from the steel tower is connected using a support unit having a temporary insulator, and the overhead power transmission line on the side away from the steel tower from the site is connected tightly. The process of supporting in
The tower side end of the overhead power transmission line is removed from the existing insulator, and the removed tower side end is pulled back to the overhead power transmission line side in a tight connection state by the support unit, and the tower is pulled back. Fixing the portion of the overhead power transmission line including a side end portion to the overhead power transmission line in a tight connection state by a fixing member;
Electrically connecting the overhead power transmission lines arranged between the steel towers and supported by the support units in a tightly connected state using a jumper unit having a metal shielded cable. ,
A construction method around the tower characterized by performing construction around the tower after these processes. A steel tower side end of an overhead power transmission line arranged across a steel tower is a construction method around a steel tower provided with an overhead power transmission line supported by the steel tower via insulators,
A connection unit between the existing insulator and the overhead power transmission line at a site away from the steel tower is connected using a support unit having a temporary insulator, and the overhead power transmission line on the side away from the steel tower from the site is connected tightly. The process of supporting in
In order to electrically connect between the overhead power transmission lines arranged between the steel towers and supported by the support units in a tightly connected state, a cable with metal shielding is provided that passes through the steel towers. A step of installing a jumper unit;
The step of removing the tower side end of the overhead power transmission line from the existing insulator and electrically connecting the removed tower side end to terminal connection portions provided at both ends of the metal shielded cable. And
A construction method around the tower characterized by performing construction around the tower after these processes.   In the connecting step, a ground wire electrically connected to the metal shielding layer of the metal shielded cable is provided along the metal shielded cable and grounded to the tower. The construction method around the steel tower according to claim 7 or 8.

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